Leveling device.



No. 704,6". Patented July l5, I902.

T. E. BROWN.

LEVELING DEVICE.

(Application filed Sept. 7, 1900.) (No Model.) 2 Shoets$heet FLlgff time oe awm'ntoz' 7 No. 704,6") Patented July l5, I902.

T. E. BRUWN.

LEVELING DEVICE.

(Application flied Sept. 7, 1900.) (No Modal.) 2 Shee ts8heet 2.

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UNlTED STATES PATENT ()FFICE.

THOMAS E. BROWVN, OF NEW YORK, N. Y.

LEVELING DEVICE.

SPECIFICATION forming part of Letters Patent No. 704,611, dated July 15, 1902.

Application filed September 7,1900. Serial No. 29,317. (No model.)

To rtZZ whom it may concern.-

Be it known that I, THOMAS E. BROWN, a citizen of the United States of America, and a resident of the borough of Manhattan, in the city of New York and State of New York, have invented certain new and useful Improvements in Leveling Devices, of which the following is a specification.

This invention relates to improvements in leveling devices.

The invention applies especially to those cases wherein a long or long and wide platform or other structure-such, for example, as a platform for raising and lowering railway-ears, a lift-lock of a canal, and other structures-is to be raised and lowered and wherein it is necessary or desirable to keep said platform or other structure level (or parallel with its original plane, if that plane be inclined to the horizontal) during all the motions and at all the positions of said platform.

For brevity I shall hereinafter designate the platform or other structure which is raised and lowered simply as the platform, including under that term all relatively long or long and wide structures, whether the same be platforms in the ordinary meaning of the term, canal-locks, or other structures.

When the platform is of considerable length or width and subject to variable loads, it is often impracticable to support it in such a manner that the center of gravity of the platform will coincide with the center of effort of the motor or motors (such as hydraulic rams) which lift the platform. In practice the loading may not be uniform or the load may be shifted in the contingencies of use, and itinevitably happens when a plurality of motors is used that some of the motors are required from time to time to support or raise greater weights than the others are required to. Even when a single motor is used one end or corner of the platformbeing the more heavily loaded will tend to remain lower if the platform is being lifted or higher if it being lowered; but if the platformis onethat is designed to be level any material departure from a true level is attended with serious consequences, and if it is designed to be at any given inclination any material departure from that inelination may also be attended with serious consequences. Therefore the problem of maintaining the platform parallel with its designed plane at all its positions and during all its movements is very important and one which from the great size of the platforms often required and enormous weights lifted has heretofore presented great engineering difliculties, which have resulted in such complicated and costly devices in attempting to solve the problem as have discouraged the use of such platforms in cases where they are rendered very desirable by the nature of the work to be done. Y

The present invention, however, solves the problem in a very simple and efficacious manner; and it consists, essentially,in operatively connecting points of the platform on different sides of the center of gravity thereof with the same point of a weight or weights heavy enough to overcome the greatest differences of load to which the platform can be subjected in the conditions of use. When the platform is thus connected with the Weight or weights, if any of the motors tends to rise more rapidly than the others or a corner or end of the platform to rise above its proper relative position the whole effect of the weight is immediately brought to bear to raise the opposite end or corner of the platform, the motor or motors thus assisted immediately restoring the lower end or corner to itstrue position. If the platform is being lowered and one end or corner tends to descend too rapidly, the whole efieet of the weight is immediately thrown on that end or corner to hold it back, and the other end, beingfreed from the restraining influence of the weight, immediately descends to its true position, and thus the platform is maintained at its designed inclination through all its movements and at all its positions.

Referring to the drawings, which accompany the specification and illustrate the in vention applied to a lift-lock and platform, Figure 1 is a broken elevation of the device, illustrating diagrammatically the application of the invention to locks. Fig. 2 is an end elevation, and Fig. 3 a plan, of the structure shown in Fig. 1. Fig. 4 is a diagram illustrating the platform or look and its connection with the weight. Fig. 5 is an isometric diagram showing a platform connected to a single weight from its corners. Fig. 6 is a plan in diagram of a similar platform, showing how separate weights may be used for leveling in each direction. Fig. 7 is a plan in diagram of a lift-lock similar to Fig. 1 or a long platform, showing how the weight may be subdivided.

In Figs. 1, 2, 3, A is a lift-lock, and B C are sections of the canal, it being understood that the ends of saidlock and canal-sections are provided with gates operated in any usual manner. The cables D E are respectively attached to the lock A, near its opposite ends, in any suitable manner, as by fastening them to the bails d e. Said cables D E are guided over sheaves F G, respectively, which are carried on the towers J K, which towers are connected by trestle-work with a larger tower L adjacent to the middle length of the lock. Said sheaves F G are inclined, as indicated in Fig. 3, so as to guide the cables D E to that side of the look at which the weight W is poised, said weight rising and descending in a shaft or space made for the purpose in the middle tower L. Numerous idlers, as j Z m 'n, maintain the said cables practically horizon tal between said sheaves F G and their respective sheaves N 0, whereby sagging of the cables, which might interfere with the elfect of the weight in leveling the lock, is obviated. From their respective sheaves N 0 said cables D E descend and are fastened at the same point to said weight W, which weight is sufficiently heavy to overcome the greatest difference inload at the two ends of the lock A which can occurin practice. The said look A is supported at a plurality of points on any suitable motors, as on the hydraulic rams P Q, the cylinders of which are so connected together and with the source of hydraulic pressure in the ordinary manner as to work in unison. Said lock and said rams are guided vertically by any suitable guides, as the dovetails 0 on the lock and flange-iron p on the towers, as seen in Fig. 3.

There is of course no limit to the number of motors, provided they are all arranged to work in unison, nor to the number of cables, provided they are all connected with the weight at the same point, and therefore in case of platforms which are relatively wide the device can be arranged to keep the platform level or at any desired inclination from side to side as well as from end to end.

In practical construction any suitable devices, as turnbuckles vor other devices, will be used to bring all the cables to the same tension.

The operation is as follows: Suppose the lock A to be rising and that any contingency causes a greater load to come on one end than on the other or that any want of perfect unison in the motors causes one to rise more rapidly than the others. Then as one end of the lock tends to rise higher than the other end the cable connecting the weight W with that end immediately slackens and a portion or all of the supporting effect of the weight is taken off that end and transferred to the lower end, which immediately causes the lower end of the lock to rise to its proper position. Conversely, if in descending one end of the lock tends to lower too rapidly a portion or the whole of the weight is immediately transferred to that end, and the higher end of the lock will at once descend to the proper level.

Fig. 5 shows a relatively wide platform 9 with its corners connected with a single weight 8 by the cables 4 5 6 7. Said cables are suitably guided over sheaves, as indicated, and are connected to the same point on the weight.

Instead of using a single weight two or more weights might be used, as in Fig. 7. In this figure each weight 10 11 is represented as connected by its cables 12 12 13 13, respectively, with the same points on the platform 14:.

In Fig. 6 the weight 1 is connected by its cables 15 16 with the corners b c and levels the platform in the direction of the diagonal b 0, while the weight 2 is connected by its cables 17 18 with the corners a. d and levels the platform in the direction of the diagonal a d.

It is obvious that any number of weights can be used, provided that each weight be connected to at least two points on different sides of the center of gravity of the platform or its load and that each weight is sufflciently heavy to equal or exceed its greatest possible share of the variable load and forces.

Now, having described my improvements, I claim as my invention- 1. In a leveling device, the combination of a movable platform, a weight, and a plurality of flexible connections connected at one end to the platform at opposing points with reference to the center of gravity thereof and at the other end to the weight at substantially the same point so that the preponderance of the weight tends to lift the low end of the platform, substantially as described.

2. In a leveling device, the combination of a movable platform, a plurality of weights, and a plurality of flexible connections operatively connecting each of said weights with said platform, and the connections which op- I eratively connect the same Weight and the platform being fastened at one end to points on said platform which are on opposites sides of the center of gravity thereof and at the other end to their respective weights, substantially as described.

3. In a leveling device, the combination of a movable platform, a weight, guide-sheaves above the platform, standards to support said sheaves, and a plurality of flexible connections guided over said sheaves and connected at one end to the platform at opposing points with reference to center of gravity thereof and at the other end to the Weight at substantially the same point so that the preponderance of the weight tends to lift the low end of the platform, substantially as described.

4. In a leveling device, the combination of a movable platform, a plurality of weights, guide-sheaves above said platform and standards to support said sheaves, and a plurality of flexible connections operatively connecting said platform and each of said weights and guided over said sheaves, and the connections which operatively connect the same weight and the platform being fastened, at one end to points on said platform which are on opposite sides of the center of gravity thereof and at the other end to their respective weight, substantially as described.

5. In a leveling device, the combination of a movable platform, one or more motors for raising and lowering the platform, a weight independent of said motors, and a plurality of flexible connections fastened at one end to points on said platform which are on opposite sides of the center of gravitythereof, and at the other end to the said weight, substantially as described.

6. In a leveling device, the combination of a movable platform, one or more motors for raising and lowering the same, a plurality of weights, and a plurality of flexible connections operatively connecting the platform with each weight, and the flexible connections which connect the platform with the same weight being fastened at one end to points on said platform which are at opposite sides of the center of gravity thereof, and at the other end to their respective weight, substantially as described.

7. In a leveling device, the combination of a movable platform, a weight, a plurality of flexible connections fastened at one end to opposing points on said platform with reference to the center of gravity thereof and at the other end to said weight, and supports adapted to maintain in a substantially straight line those portions of said flexible connec tions which are not vertical, substantially as described.

8. In a leveling device, the combination of a movableplatform, a plurality of weights, a plurality of flexible connections operatively connecting each of said weights with said platform, and the connections which operatively connect the same weight and platform being fastened at one end to opposing points on said platform with reference to the center of gravity thereof and at the other end to their respective weight, and supports adapted to maintain in a substantially straight line those portions of said flexible connections which are not vertical, substantially as described.

Signed at New York city this 30th day of August, 1900.

THOMAS E. BROWN.

Witnesses:

HENRY V. BROWN, BERNARD J. ISECKE. 

